Welcome to healthcaremagic
i would like toknow in detail your history. the information given by you is not sufficient to say whether you require joint replacement
i suggest that you meet an orthopaedics with your xray report . he will decide whether you require the TKR or not.
At the age of 40 the Total Knee Reeplacment is rare done. It is not recommend unless there is no other way
Wish you good health